This thesis explores literary narratives, legal frameworks, medical practices, and ritual performances in order to shed light on the complex connections between ritual forms of magic, public perception, and the authorisation granted by the public for the performance of magical rituals. The research is presented through six chapters, each of which examines a magical practice through select texts. Chapter 1 lays out the keywords and phrases that will be used throughout the rest of the thesis, and defines them in such a way that the work that follows is easier to read. This includes defining such terms as ‘magic’ itself, as well as ‘charm’, ‘love magic’, and ‘curse’ so that they are reduced to neutral terms, with modern or cultural biases removed from them. Chapter 2, then, examines some representations of miracles and magic in hagiographical texts by looking at events in the Tripartite Life of St Patrick through the lens of similar events in the life of Moses. This is set alongside a discussion of miracles in the Lives of St Brigit, with particular regard to how they reflect social and gender norms of the period, while also reflecting charming practices that will be seen in Chapter 3. Chapter 3 turns to the genre of medical texts to explore the concept of miraculous healing. Specific examples are taken from a previously unpublished collection of blood-staunching remedies from Dublin, National Library of Ireland MS G11; a full transcription and translation of these remedies is provided in the Appendix. Chapter 4 explores the practice of satire as imprecation in early Ireland. The codes and procedures relating to the filid and the practice of satire are discussed, as well as the clerical form of ritual cursing, which explicitly endorsed and permitted the practice of this style of ‘word-magic’ in society. Chapter 5 draws on evidence from select texts to explore how magical practices might be directed at inducing love or affection in another individual. This material is set against the wider background of representations of magic in Carolingian writings on the divorce of King Lothar and Queen Theutberga. Chapter 6, then, draws on ritual theory to consider the possible psychological and emotional aspects of these performances on their audiences.